Colorado River Water Resources Vulnerability

Project for Hill Country Conservancy

Daniel Zavala Araiza

Outline

• Hill Country Conservancy

• Defining vulnerability

• Mapping vulnerability

• Methodology

• Results

• Conclusions

- Outline -

• Land preservation agreements.• Conserve a property in its natural state.• Land conservation -> impact on aquifer system.

- Hill Country Conservancy -

Development of a tool that is useful in determining which parts or parcels of land are more valuable in terms water resources vulnerability to focus

on their preservation.

- Objective -

Yildirim, M., and Topkaya B., (2007), Groundwater Protection: A Comparative Study of Four Vulnerability Mapping Methods. Clean 35 (6), 594 – 600.

Intrinsic geological + hydro geological characteristics which determine sensibility of groundwater/surface water to contamination.

intrinsic vs. specific

- Defining Vulnerability -

•All kinds of pollutants•Vulnerability mapping

•Point sources (oil spills, leakage)•Risk mapping

- Mapping Vulnerability -

Yildirim, M., and Topkaya B., (2007), Groundwater Protection: A Comparative Study of Four Vulnerability Mapping Methods. Clean 35 (6), 594 – 600.

- Selected Parameters -

Soil thickness Soil KSAT

Slope Vegetation

How much filtration?Amount of water that can be absorbed.

-

+ thin

thick

How easily water flows through the soil.

-

+ high

low

How likely water is to runoff?

-

+ steep

flat

How much water will be impeded by vegetative cover?

-

+*ranking based on amount of ground cover

- Creating layers -Soil thickness

Soil KSAT

Slope

Vegetation

SSURGO

NED(USGS)

*raster

NLC(USGS)

*raster

HCC study area

Reclassify

Vulnerability map

Weighted sum

• Soil Survey Geographic Database (SSURGO)

- Soil Datasets -

Soil Survey Geographic Data Base Data Use Information, USDA, 1995,pp.110

Soil Data Viewer for ArcMap

Soil ThicknessKSAT

- Layers -

Slope Vegetation

- Results -

- Results -

Edwards Aquifer

Hickory Aquifer

• Add Cave Density as parameter.

• Compare groundwater to surface water

vulnerability

• Sensibility analysis for relative importance of

parameters in weighted sum.

- Further work -

• Vulnerability mapping as a valuable tool.

• Couple their use with other methods (risk mapping).

• Importance of parameters selected and their weight.

- Conclusions -